1. Field of the Invention
This invention is generally directed to cleaning machines and more specifically to continuous conveyor type cleaning and degreasing machines which may be utilized to remove greases, oils, tars and various other residues from machinery parts, tools and articles of manufacture. The machine includes a parts transporting conveyor which carries the articles to be cleaned through a cleaning chamber filled with a cleaning solution and wherein the articles or parts are subjected to a series of opposing torrents of cleaning solution. The turbulent flow and agitation achieved by the flow of solution insures that substantially all of the oils, greases and other residues are removed from the parts or articles. The degreasing and cleaning machine is not only continuously operable, but the cleaning solution is also continuously purified by being passed through a non-turbulent containment chamber which is in fluid communication with the cleaning chamber and wherein greases, oils and other contaminants are separated and removed therefrom.
2. History of the Art
Industrial type cleaning machines have been used not only to remove greases, dirts, oils and residues from old machinery parts but also to clean manufactured items which have been left with oily residues as a result of the manufacturing process. Cleaning old parts or components enable such items to be rejuvenated for extended periods of additional use thereby prolonging the service life of older machines and equipment.
During the continued operation of many machines, the lubricants which are utilized to reduce friction and wear and tear of the interacting parts begin to collect or cake on such components. In addition, dirt, dust and small particles of production debris become embedded in the lubricating material causing undesireable build ups and deposits of such materials on the machine components. In some instances, in order to permit continued operation of a machine, it becomes necessary to dismantle the machine and clean the deposited materials from the various operating parts or components. This cleaning may be part of a scheduled maintenance program or may be done as part of a restoring or rebuilding program.
Various types of cleaning units have heretobefore been designed to accomodate the degreasing and cleaning of machine parts and the like. Some of these units operate as batch type cleaners wherein a single load of parts are immersed in a solvent or cleaning solution and allowed to soak over a period of time. Thereafter, the parts are withdrawn from the cleaning fluid and the fluid containing the contaminant oils and greases discharged. Such simple batch processes have the disadvantage of being both slow and inefficient as well as being costly. The costs of cleaning solvents are such that methods which require the solutions to be discharged after one or a limited number of uses cannot be practiced economically. Further, processes which provide for subsequent filtering and separation of oils and greases from discharged solvent solutions in order to reduce solvent costs require additional fluid handling equipment and are also labor intensive.
Other disadvantages in the single batch type processes are that such processes are inherently slow and not always thoroughly effective in totally or adequately cleaning the parts being treated. To improve the overall cleaning effectiveness of batch processes, use has been made of heaters to increase the temperatures of the cleaning solvents and mixers or agitators to create greater fluid turbulence. With increased solvent temperatures and increased fluid movement, not only were cleaning efficiencies improved but cleaning cycles or rates were also reduced.
In some other prior art cleaning units, use has been made of fluid sprayers to facilitate the removal of impurities from the surface of parts or components being cleaned. Such prior art sprayers are used to direct high velocity jets of cleaning fluids toward components being processed in order to dislodge materials or contaminants therefrom. The use of fluid jets or sprays has been ineffective in removing more stubborn and built up layers of grease and dirt.
Hybrid cleaning systems have also been developed which incorporate combinations of solvent sprays and batch type processing of parts being cleaned. In these systems, the parts are subjected to either or both initial and post fluid sprays while being intermittently submerged in the batch cleaning solutions. Such hybrid systems also have their disadvantages. Not only do such systems require additional parts conveying equipment but the fluid sprays cause small particles of solvent to become air borne thereby necessitating the use of special ventilation equipment to maintain the environment and air quality in the area in which such systems are used.
In order to obtain an efficient and reliable parts degreasing and cleaning machine which provides for the continuous use of the cleaning solvent, applicant designed and developed a system which is described in copending U.S. patent application, Ser. No. 750,200, filed July 1, 1985. In this system, the cleaning fluid or solution is predominantly retained and cycled through fluid headers disposed in direct communication below the surface of the fluid within the parts cleaning chamber. A small portion of the fluid being recycled to create turbulence within the part cleaning chamber is allowed to pass into a non-turbulent chamber wherein the greases, oils and other contaminants are separated by gravity and then removed by skimming the surface to remove such contaminants from the cleaning solution.
Although applicant's copending process and apparatus provides for a cleaning system which conserves solvents, the system still operates as a batch system and therefore is not always conducive for use in some types of cleaning environments.
Some other examples of the prior art degreasing and cleaning machines include U.S. Pat. Nos. 2,385,860 to Jesson, 2,989,027 to Schouw, 3,242,933 to Huff and 4,092,991 to Rohrs.